Fig. 4.

Cytotoxicity, biocompatibility, and biodegradability. (A) Cytotoxicity experiments of PP formulation 1 at different dilutions exhibiting the relative cell apoptosis compared with an untreated control using HDFa cells (mean ± SD; n = 8). (B) BOD measurements (mean ± SD; n = 3) illustrating the materials to be environmentally benign as these materials do not aerobically degrade and do not inhibit aerobic degradation processes. The abrupt decrease in dissolved oxygen observed for all samples at day 12 is due to ammonium oxidation. (C) BMP experiments (mean ± SD; n = 3), plotted as liters of methane per kilogram of COD, illustrating slow anaerobic degradation of the PP formulation, enabling persistence in the wildland over the timeframe of the peak fire season.